The objectives of this research are: a) to discover enzymes that participate in processing of RNA in Escherichia coli; b) to find out the structural genes that govern these enzymes; c) to understand the process of RNA maturation, particularly rRNA. These objectives will be aimed at by: (1) purifying various RNA processing enzymes and understanding their mode of action; (2) isolating bacterial strains defective in known and as yet unknown processing ribonucleases; (3) analyzing genetic strains carrying suc mutations (location, dominance, recessivity); (4) studying the physiology and RNA metabolism in strains carrying single and multiple mutations affecting RNA processing. Many of these studies will be carried out by analyzing RNA from cells in sucrose gradients, or in polyacrylamide gels, and by qualitative and quantitative analyses of such gradients and gels, as well as by fingerprinting and sequencing of some of these RNAs.